Remove particles.js source, keep only compiled dist file

Replaces particles.js-master/ (full library source with old npm deps)
with just particles.min.js at the repo root. Clears 37 GitHub security
vulnerability alerts caused by outdated build dependencies (gulp, jshint, etc.).
Updates script src in index.html accordingly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: thomasgudjonwright

index.html

@@ -5,7 +5,7 @@
     <meta name="author" content="Thomas Wright">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <link rel="stylesheet" type="text/css" href="styles.css">
-    <script src="particles.js-master/dist/particles.min.js"></script>
+    <script src="particles.min.js"></script>
     <!-- Global site tag (gtag.js) - Google Analytics -->
     <script async src="https://www.googletagmanager.com/gtag/js?id=G-Z8VGSFNZ19"></script>
     <script>